U.S. patent number 4,812,980 [Application Number 06/863,520] was granted by the patent office on 1989-03-14 for map display system.
This patent grant is currently assigned to Nippondenso Co., Ltd.. Invention is credited to Hidetoshi Fujimoto, Kazunori Hanabusa, Kenzo Ito, Takeshi Yamada.
United States Patent |
4,812,980 |
Yamada , et al. |
March 14, 1989 |
Map display system
Abstract
In a map display system, map-forming data necessary for display
of a display area and character data representing display areas are
stored in a map data memory. A display area commander reads
map-forming data indicating a specified display area out of the map
data memory, and produces a display area instruction. A display
character commander selects character data for a given point of the
specified display area designated by the display area designation
commander, and produces a display character instruction. On the
basis of the display area instruction from the display area
commander and the display character instruction from the display
character commander, a map of the specified display area and
characters in the specified display area are displayed on a
display.
Inventors: |
Yamada; Takeshi (Seto,
JP), Fujimoto; Hidetoshi (Toyokawa, JP),
Ito; Kenzo (Okazaki, JP), Hanabusa; Kazunori
(Kasugai, JP) |
Assignee: |
Nippondenso Co., Ltd. (Kariya,
JP)
|
Family
ID: |
14385961 |
Appl.
No.: |
06/863,520 |
Filed: |
May 15, 1986 |
Foreign Application Priority Data
|
|
|
|
|
May 16, 1985 [JP] |
|
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60-104637 |
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Current U.S.
Class: |
701/532; 340/990;
340/995.15; 701/455 |
Current CPC
Class: |
G06T
17/05 (20130101); G09B 29/106 (20130101) |
Current International
Class: |
G09B
29/10 (20060101); G06T 17/50 (20060101); G06F
015/50 (); G09B 029/00 () |
Field of
Search: |
;364/424,443,449,460,521
;73/178R ;340/988,990,995 ;342/450-452 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
"The 44th Study Meeting" Sep. 5, 1984, Mitsubishi Elec. Corp. pp.
7-9..
|
Primary Examiner: Chin; Gary
Attorney, Agent or Firm: Cushman, Darby & Cushman
Claims
We claim:
1. A map display system comprising:
memory means for storing map-forming information required for
display of a map of a predetermined area and storing coordinates of
a predetermined spot within said predetermined area and a display
character code representing the name of the predetermined spot,
said display character code being formed by a plurality of letters,
the entirety of each said display character code being associated
with said coordinates of said predetermined spot corresponding to
said display character code;
designating means for designating a scale of the map;
display means for displaying the map; and
display control means for reading out the mapforming information
from said memory means and for causing said display means to
display the map of the scale designated by said designating means,
said display control means further causing said display means, in
accordance with the coordinates and the display character code of
the predetermined spot stored in said memory means, to perform a
character display of said name on a position corresponding to said
coordinates of the predetermined spot on the map displayed by said
display means, said character display being positioned in
accordance with the coordinates of the predetermined spot, the size
of the characters and an interval between adjacent characters being
maintained at a fixed value regardless of the scale designated by
said designating means.
2. A system according to claim 1, wherein said display control
means comprises means for causing said display means to display a
mark indicating a position of the predetermined spot at a position
corresponding to said coordinates of the predetermined spot on the
map displayed by said display means, and for causing the character
display of the name of the predetermined spot on a predetermined
display portion of the display means using the display character
code stored in said memory means.
3. A system according to claim 1, wherein said display means
comprises means for changing the number of displayed characters of
a name to be displayed in accordance with the scale designated by
said designating means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a map display system for guiding a
vehicle such as a car.
Various suggestions have been made about a map display system of
this type in the prior art.
An example is disclosed in Japanese Patent Laid-Open Publication
No. 164583/84 invented by the present applicant. In this system,
map pattern data providing the basis of display of roads and the
like on a display screen and character data providing names of
municipalities, roads and the like are both stored as code data, so
that with the driving of the vehicle, map patterns and descriptive
characters are indicated on the display screen automatically or by
the operation of the driver.
Indication of all character data included in a given map area on
display makes it difficult to see the map as a great number of
display data characters are involved. For this reason, there is
needed some display limitation.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a map display
system in which character data are provided as a data base
independent of data for preparing a map, so that characters are
displayed always in the same size regardless of the scale of the
map which may be enlarged or reduced by a map display designation
on the one hand, and the characters are made easily recognizable on
the other hand. That is the interval between characters is kept
constant.
In order to achieve the above-mentioned object, according to the
present invention, there is provided, as shown schematically in
FIG. 1, a map display system comprising map data memory means for
storing map-forming data required for display of each display area
and character data corresponding to each of said areas; display
area designation means for reading the map-forming data
corresponding to a specified display area from said map data memory
means and producing a display area instruction; display character
designation means for selecting only the character data
corresponding to defined components constructing the specific
display area designated by said display area designation means and
producing a display character instruction; and display means for
displaying the map of the specified display area in response to the
display area instruction from said display area designation means
and displaying characters in response to the display character
instruction from said display character designation means in said
display area.
A map display system further comprises character form control means
for maintaining the size of the characters displayed on the display
means and the interval between characters to a fixed level
regardless of the display scale of the display area.
A map display system further comprises number-of-characters control
means for changing the number of characters displayed on the
character display means in accordance with the scale of the display
area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a configuration of the present
invention.
FIG. 2 is a block diagram showing an embodiment of the present
invention.
FIG. 3 shows a data configuration of character data.
FIGS. 4 and 5 are flowcharts for explaining the processing
operation of a CPU.
FIGS. 6 to 11 are diagrams showing forms of map and display screens
for explaining the transfer of screen display forms.
FIG. 12 is a flowchart showing displays of display data according
to type codes and designation codes of descriptive data.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A configuration of an embodiment of the map display system
according to the present invention is shown in FIG. 2. In this map
display system, a system 1 includes a well-known microcomputer
having a CPU 1a, a ROM 1b, a RAM 1c, an input port 1d and a common
bus 1e, and a CRT controller 1f. The system further comprises input
means including a direction sensor 2 for detecting the direction in
which the vehicle is running, a distance sensor 3 for detecting the
distance covered by the vehicle, a control panel 4 operated by the
driver, and a reader 5b with a replaceable magnetic disc 5a, which
input means are electrically connected to the system proper, and
output means including at least a CRT display 6 electrically
connected thereto for displaying map patterns such as roads and
characters.
The direction sensor 2 includes an annular permalloy core, an
excitation coil and two coils intersecting each other at right
angles, and produces a direction signal for detecting the vehicle
running direction against the earth's magnetism on the basis of the
output voltage of the two coils.
The distance sensor 3 detects the revolutions of a speed meter
cable indirectly as an electrical signal through a reed switch, a
magnetically sensitive element or a photoelectric cell, or detects
the revolutions of the output shaft of the transmission as an
electrical signal in a similar manner, thereby producing a distance
signal used for computing the distance covered by the vehicle.
The control panel 4 includes at least a switch (not shown) for
supplying and interrupting power to the map display system from a
battery mounted on the vehicle, enlargement and reduction keys (not
shown) which are operated by the driver for designating an enlarged
or reduced display of the map, and a display key (not shown) which
is operated by the driver for designating the display of a
description on the screen of the CRT display 6.
The magnetic disc 5a stores map patterns as pattern data and
character data corresponding to appropriate geographic points on
the map as code data. Assume that characters "ABC City", "DEFG",
"HIJKL" and "MNO" are to be displayed, for example. As shown in
FIG. 3, each of the character data is made up of a set of data
elements including a display character code, an X coordinate of the
position, a Y coordinate of the position, a pilot code display
scale, a single-character display scale, a double-character display
scale, a three-character display scale, . . . . . , a n-character
display scale.
The ROM 1b of the system proper has a program stored therein by
which the CPU 1a executes the processes shown in the flowchart of
FIG. 4.
The CPU 1a repeatedly executes the processes (1) to (12) described
below.
(1) Whether or not the enlargement key is turned on (step 101 in
FIG. 4) is decided.
(2) If it is decided that the enlargement key is turned on, the
enlargement process is executed (step 102). The specific operation
of the enlargement process will be described later.
(3) After execution of this enlargement process, or if it is
decided that the enlargement key is not turned on by the step 101,
then it is decided whether or not the reduction key has been turned
on (step 103).
(4) If it is decided that the reduction key has been turned on, the
reduction process is executed (step 104).
(5) After execution of the reduction process or if it is decides at
step 103 that the reduction key has not been turned on, then the
direction signal from the direction sensor 2 and the distance
signal from the distance sensor 3 are received to compute the
present position of the vehicle in a well-known manner (step
105).
(6) The present position obtained by the above computation is
compared with the geographic point corresponding to the descriptive
data, that is, the descriptive point thereby to decide whether or
not the present position coincides with the descriptive point (step
106).
(7a) If it is decided that the present position does not coincide
with the descriptive point, the process is passed to the
computation of the present position (step 105).
(7b) If it is decided that the present position coincides with the
descriptive point, on the other hand, the description based on the
descriptive data corresponding to this descriptive point is
displayed on the screen of the CRT display 6 through the CRT
controller 1f or the description on display on the screen of the
CRT display 6 is erased (step 107).
(8) It is decided whether or not the abovementioned description is
the one required to be stored in the RAM 1c, such as a radio
broadcasting station with the receiving frequency thereof or a
telephone number of JAF (step 108).
(9) If it is decided that the description is the one to be stored,
the particular descriptive data is stored in the RAM 1c (step 109),
and the description, after being displayed for several seconds on
the screen of the CRT display 6 through the CRT controller 1f, is
erased (step 110).
(10) After the end of the process of the step 110, or after it is
decided at step 109 that the description involved is not the one
required to be stored such as "Narrow road" or "Beware of falling
stone", then it is decided whether or not the display key has been
turned on by a signal from the display key on the control panel 4
(step 111).
(11) If it is decided that the display key has been turned on, the
description based on the descriptive data stored in the RAM 1c is
displayed on the screen of the CRT display 6 through the CRT
controller 1f (step 112).
(12) After execution of, the process of the step 112, or if in the
step 111 it is decided that the display key has not been turned on,
then process is passed to the step 101 for deciding whether the
enlargement key has been turned on or not.
Essential parts of the aforementioned enlargement processes are
specifically shown in FIG. 5. These processes will be explained
below.
(1) A display scale coincident with the scale designated by the
enlargement key operation is determined (step 1021). In other
words, it is decided whether or not the designated scale coincides
with the pilot code display scale, the one-character display scale,
the two-character display scale, the three-character display scale,
. . . . . or the n-character display scale, or it does not coincide
with any of the display scales. This step 1021 is executed only for
one of a plurality of display characters once each time of
process.
(2a) If the designated scale fails to coincide with any of the
display scales, the positional coordinate (x, y) determined in
advance in correspondence with the display character is transferred
to the display screen, and the mark "X" or ".DELTA." is attached to
the coordinate position (step 1022).
(2b) When the designated scale coincides with the pilot code
display scale, on the other hand, the pilot code is displayed at
the display coordinate position in the same manner as above (step
1023). At the same time, a correspondence table is displayed at the
upper right corner of the screen as viewed from the operator (step
1024). This correspondence table is displayed in such a form as "a:
ABC City" if the display characters are "ABC City" and the pilot
code is "a", for example.
(2c) If the designated scale coincides with the i-character display
scale, such as the double-character display scale, for instance, it
is decided whether these two characters coincide with all the
display characters (step 1025). Assuming that the display
characters are "ABC City", for instance, the characters involved
are seven in all, and therefore it is decided that they fail to
coincide with each other, so that the display color is changed
(step 1026). This display color change is a process for changing
the color of the characters to be displayed next. After this
display color change or the step 1025 decides that all the
characters coincide, the characters to be displayed are displayed
in color at the display coordinate position (step 1027).
(3) After the process of (2a), (2b) or (2c) above, it is decided
whether or not the process has been completed for all the display
characters (step 1028), and if all the data is not completely
processed, the step 1021 is executed again for the next display
characters. If all the data is completely processed, by contrast,
this routine is left.
In parallel to this enlargement process, the form of display screen
described below is achieved according to the designated scale.
Specifically, in the case of a map comprising patterns and
characters as shown in FIG. 6, assume that the designated scale is
minimum, that is, display of the whole map is designated. In view
of the fact that roads are so densely located that a character
display thereof is not legible, only the marks "X" and ".DELTA."
are attached at the display positions based on the coordinate (x,
y) as shown in FIG. 7. In the case of a designated scale a rank
higher, the pilot code "a" is displayed only for ABC City, together
with the correspondence table "a: ABC City" at the upper right
corner at the same time as shown in FIG. 8. Further, on the other
hand, "AB" alone of "ABC City", "DE" alone of "DEFG" and "HIJ"
alone of "HIJK" are displayed as shown in FIG. 9, while at the same
time displaying the whole of "MNO". If the designated scale is a
greater rank, the whole of "ABC City" and "HIJKL" and "DEF" alone
of "DEFG" are displayed as shown in FIG. 10. As can be seen from
these figures, the interval between adjacent characters remains the
same regardless of the scale of the map.
Now, explanation will be made of the manner in which the display
form of the screen of the CRT display 6 undergoes a change with the
progress of the vehicle with reference to the steps 105 to 112 in
the flowchart of FIG. 4 described above.
The roads displayed on the screen of the CRT display 6 have
descriptive points (P.sub.2, P.sub.3, P.sub.4, . . . ) for
displaying service data of various types, so that sentences of the
descriptive data are displayed on the screen of the CRT display 6
when the vehicle passes each descriptive point.
(1) When the vehicle having passed the point P1 shown in FIG. 11
reaches the descriptive point P2, the data "Beware of falling rock"
is displayed at a part of the screen, such as at the lower part
thereof.
(2) Subsequently when the vehicle having passed the point where he
was warned against falling rock reaches the descriptive point P3,
the display "Beware of falling rock" is erased.
(3) Subsequently when the vehicle reaches the descriptive point P4,
the telephone number of JAF (corresponding to AAA) such as "JAF
.DELTA..DELTA.- 0000" is displayed for several seconds.
(4) Subsequently when the vehicle reaches the descriptive point P7
through the points P5 and P6, the receiving frequency such as "A
broadcasting station xxxxx KHz" is displayed for several
seconds.
(5) After that, when the vehicle reaches the descriptive point P9
through the point P8, the receiving frequency "B broadcasting
station 0000 KHz" is displayed for several seconds.
(6) Then, when the vehicle reaches the descriptive point P13
through the points P10, P11 and P12, "Narrow road" is displayed at
a part of the screen.
(7) After that, when the vehicle reaches the descriptive point P14
through the narrow road, the display "Narrow road" is erased.
As described above, in the case where a vehicle makes progress as
shown in FIG. 11, the display form of the screen changes as
specified from (1) to (7) with the progress of the vehicle.
However, if the display key of the JAF telephone number or other
key is operated after the vehicle has passed the descriptive point
P4, for instance, the telephone number of JAF or the related data,
as the case may be, is displayed by the operation of the display
keys.
The steps 106 to 112 in the flowchart of FIG. 4 will be explained
more in detail below.
As shown in Table 1, the display data, designation codes and type
codes are stored in the magnetic disc 5a in correspondence with the
coordinate data of the respective descriptive points (P.sub.2,
P.sub.3, P.sub.4, . . . ).
TABLE 1 ______________________________________ DESCRIPTIVE POINT
DATA Position of descriptive Type Designation point Display data
code code ______________________________________ P2 (x.sub.p2,
y.sub.p2) Beware of falling 1 1 rock P3 (x.sub.p3, y.sub.p3)
"Beware of falling 1 2 rock" cancelled P4 (x.sub.p4, y.sub.p4) JAF
.DELTA..DELTA.-OOOO 2 3 P7 (x.sub.p7, y.sub.p7) A broadcasting sta-
3 3 tion xxxx KHz P9 (x.sub.p9, y.sub.p9) B broadcasting sta- 3 3
tion xxxxx KHz . . . . . . . . . . . . P13 (x.sub.p13, y.sub.p13)
Narrow road 1 1 P14 (x.sub.p14, y.sub.p14) "Narrow road" 1 2
cancelled ______________________________________ DESIGNATION CODES:
1: Data displayed while a caution instruction is issued. 2: Data
for designating the cancellation of the data on display. Displaye
for several seconds. 3: Data displayed for several seconds and
stored the RAM data. This data becomes an object of operation
display. TYPE CODES: 1: Caution data 2: JAF data 3: Broadcasting
station data
The descriptive data shown in Table 1 are processed in accordance
with the flow chart shown in FIG. 12. In the flowchart of FIG. 12,
the display data is displayed and stored in the RAM 1c in
accordance with the designation code and the type code of each
descriptive data. The caution data with the type code of "1", for
instance, is not required to be displayed after the vehicle has
passed the particular point, and therefore is not stored in the RAM
1c. As to the JAF data or the broadcasting station data with the
type code of "2, 3", however, they are stored in the RAM 1c, since
the telephone number of JAF or the receivable frequency of the
broadcasting stations is necessary in case of emergency even after
the particular descriptive point has been passed. When the user
operates the display keys, therefore, the descriptive data is read
out and displayed from the RAM even after the particular
descriptive point has been passed.
Storage addresses corresponding to each descriptive data are
predetermined in the RAM, and they are rewritten as the latest data
each time the descriptive points are passed.
In the case where the data in the RAM is displayed at step 112,
only that data with the type code of "2" or "3" is picked up from
Table 1 and displayed. The display keys may be adapted for
displaying each type code each time of operation thereof.
* * * * *